Typewriting machine



April 21, 1925 B.. C. STICKNEY TYPEWRITING MACHINE Filed May 20, 1921 5 Sheets-Sheet l April 21,- 1925.

B. C. STICKNEY TYPEWRITING MACHINE a Sheets-Sheet 2 Filed May 20, 1921' 'Apkil 21, 1925.

B. C. STICKNEY TYPEWRITING MACHINE 5 Sheets-Sheet 5 Filed May 20, 1921 Illllilll. I

Patented Apr. 21, 1925.

UNITED STATES BUItNZELAM o. STICKNEY, OF ELIZABETH,

PATENT OFFICE.

JERSEY, ASSIGIl'OR TO UNDERWOOD TYPEWRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE TYPEWRITING MAGEIN E.

Application'filed May 20, 1921. Serial No. 471,173..

To all whom it may concern:

Be it known that I, BURNHAM C. STICK- NEY, a citizen of the United States, residing in Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Typewriting Machines, of which the following is a spet-ification. A

This invention relates to sound-deadening hoods or casingsfor typewriting machines, and is of the same general type disclosed in my co-pending application, Serial'No. 429,- 617, filed December 10, 1920 (now Patent No. 1,519,224, dated December 16, 1924). l

The invention comprises, in combination with a typewriting machine, a sound-dead-' emug casing 61' hood for enclosing the noiseproducing parts .of the typewriting machine, while the keys and other parts of the machine used in itsoperation, which are suitably arranged for the purpose, project through the hood.; 1

The invention provides for a longitudinal slotat the front between a lower body or part and an upper, rearwardly-swingable, hinged (over, dome or part, beneath which aplurality of carriage-controlling fingerpieccs may project, said finger-pieces working in said slot. The carriage in the present invention may be mounted to travel within the cover part between'the end walls thereof.

It is one feature of this invention to 'provide a sound-mufliing means, in addition to the sound-deadening hood, by closing the passages in the frame of the typewriting' machine through which sound was-hitherto able to issue freely from the machine to the casing.

Another feature of this invention is the provision of 'mea-ns for transmitting the sound of the line-end bell-signal to the exterior of the sound-deadening casing. The bell-signal is ordinarily mounted on the frame of the typewriting machine and conse-' quently within the casing, but in the present invention the bell is extended laterally to project through the sound-deadening (as ing, the parts cooperating with the bell-signal being suitably modified.

Another feature of this invention i's the provision'of means whereby the platen may berotated as freely in either direction from the exterior of the hood as by the ordinary linger-wheels or knobs,,and for this purpose a shaft having finger-wheel at its forward end projects through the front slot in the Other features and advantages will hereinafter appear.

In the accompanying drawings,

5 Figure 1 is a front elevation of the sounddeadening hood applied to an Underwood standard typewriting machine as modified by the invention.

Figure 2 is a plan view of the device shown in Figure 1, the cover part of the hood havin been removed to ex ose the interior.

1 Figure 3 is a detail showing the bell-signal as applied to the machine in the present invention.

"Figure 4 is a vertical section of thehood taken on the line 44 of Figure 1.

The Underwood standard typewri ting machine comprises a main frame 10 and a forward extension 11 of said frame, within.

which extension are positioned banks of keys 12 fixed to the ends of key-levers 13, which operate bell-cranks 14 to swing typebars 15 upwardly and rearwardly to strike against the platen 16. Said platen is fixed upon a shaft 17 journaled in the end walls 18 of a platen frame 19 forming part of the usual carriage 20, which rides on a. front rail (not shown), and a rear rail 21. The platen may be rotated within-the hood by a finger-wheel or knob 22 fixed to one end of the shaft .17, and may be line-spaced from the outside of the hood by a handle 25 (of a form to be described hereinafter) operating the usual line-space mechanism comprising a slide 26. The platen-may be rotated in either direction by additional means projecting outside the hood, said means comprising a finger-wheel 30 at the endof a forwardly-projecting rod 31 having a universal joint 32 at a point intermediate its length to allow for ease-shifting of the platen, and having a gear 33 at its end meshing with a similar ear 34 fixed on the end of the platen shaft 1 The gear 34 is staked to shaft 17 which is journaled in one end of a supporting bracket 35, the other end of which is fixed to the wall 18 of the platen frame 19, and the gear 33 is staked to the rearward portion of rod 31, which is journaled in a hub 37 at one end of a substantially right-angled bracket 38 having a hub 39 in which the shaft 17 is journaled, the bracket 38 being so proportioned that the gears 33' and 34 will be held in meshing engagement. When the platen is shifted, the shaft 17, the bracket 38, and hence gears 33 and 34 and the rearward portion of rod 31 will move as a unit, the universal joint 32 permitting the rearward portion of rod 31 to move relatively to the forward portion, which is held to the non-shifting carriage frame by a bracket 40 fixed at one end to the carriage frame and having a hub 41 at the other end in which the forward portion of rod 31 is journaled. The carriage is provided with the usual carriagesreleaselever 42 which has a forward extension 43, a carriage-return finger-piece 44 fixed to said carriage, and the usual pointer 45 co-operating with a scale 46 on the main frame of the machine, the form of said lever 42 and finger-piece 44 being described more fully hereinafter.

The typewriting machine rests upona sound-deadening base-plate or pad 50, which forms the bottom plate for the sound-deadening casing or hood, the latter comprising a lower, body portion 51 and an upper or cover portion 52. The body portion comprises a front wall 53, end walls 54, and a rear wall 55, the front wall being provided with an opening large enough to receive the main typewriter frame 10. The body portion has extensions 56 forming a container at either side in which the carriage travels to the right and left. The cover portion 52 is hingedly connected by a rear wall 57 to the rear wall 55 at 58, and comprises side walls whlch co-operate with the outer limits of the extensions 56 of the body part, a for-' wardly-extending and downwardly-sloping top wall 60, which may be a continuation of the rear wall 57, and a short front wall 6 1 terminating some distance below the top of the carriage and considerably above the top edge of the front wall 53 of the body part. The top wall 60 is provided with transparent plates 62 supported in any well known manner, as by bars 63 forming grooves for receiving the plates and facilitating replace ment, said plates occupying substantially the entire top wall, thus rendering visible the typing of work-sheets around the platen. The plates 62 are spaced from each other in order to prevent more effectually the transmission of sound therethrough, and are held in place by suitable clamps 59. The various parts of the body part and cover part of the casing heretofore described are held together and re-enforeed in any well known manner, as by angle-iron's64. 1

It will be apparent that the front wall 53 of the body part terminates at its top a distance below the carriage to permit the typewriter to slide into the hood from the front. The front wall 61 of the cover part terminates about midway of the platen, thus leaving a large opening in the front of the hood. To partially close this opening, there is provided a releasable front cover-plate shaped like the front wall 53 but extending upwardly a greater distance, said coverplate being mounted, by large openings or key-hole-slots 72 on studs 71 passing through the front wall 53 and lodging in the angleirons 64-. The cover-plate is then lowered, the studs passing upwardly in extensions of said openings which are narrowed suflieiently to prevent the cover-plate from sliding off the heads of thestuds. The coverplate is then fixed by means of screws 74 passing into the front wall and the angleirons 64. It will thus be seen that, by merely removing screws 7 4 and lifting plate 70 upwardly to bring the large openings 72 opposite the studs, the cover-plate may be readily removed. i

The upper edge 75 of the front cover-plate does not reach the lower edge 76 of the front wall 53-, thus leaving a slot 80, which is closed to prevent the escape of sound, there being provided for this purpose upper and lower slot-closing cushion strips 81 and 82, which may be formed of aloop or fold of suitable material, such as plush, felt or soft leather. The upwardly-extending two-ply margin of the upper cushion strip 81 is cured upon the inner side of the front wall 61 adjacent the lower edge thereof, and the lower cushion strip is similarly secured upon the 1nner slde of cover-plate 70 ad acent the 'npper edge thereof by means of clamping strips 83 held in place by any suitable means such as screws or rivets. The cushion strips 81 and 82 meet on aline slightly below the level of the platen axis. It is desirable to operate the machine, that is, to line-space the platen, return'the. carriage to the right, release the carriage from the rack, and retate 'the platen, whenever desired, without lifting the cover of'the hood. Since the linespace handle 25, carriage-return finger-piece 44 and carriage-release-lever extension 43 are mounted on a level with the front bar 47 of the carriage, it is necessary to curve these members downwardly, as well as ext-end them forwardly to project through slot 80. The finger-wheel. 30 for rotating the platen projects through the slot on the forward portion of rod 31 in amanner similar to the levers and finger-pieces mentioned above.

be closed by layers 95.

It has been found that a substantial portion of-the noise produced by the operation of a typewriting machinecan be eliminated by mufiling means before the sound passes outside the main frame 10. For this purpose, sound-deadening material is provided to close the open side, front, and rear walls, and the bottom of the spaces between the feet of the machine as well as the space beneath the key-levers. The bottom of the frame is closed by a strip 90 of felt or other sound-deadening material resting on the base 50, and of a thickness to fill the space-between the base and the bottom of the frame 10, said space being due to the frame supports or .feet 91. The strip occupies the substantially rectangular space between the feet 91. The frontof the main frame is'partially open, beneath the guide plate or comb,92 in which operate the keylevers, and to close this'space a layer 93 of sound-deadening material is provided between the front feet 91, said layer extending upwardly from the pad 50 and terminating a short distance below the keylevers to allow free downward movement of the latter. ,A similar layer 9-1 is provided for closing the entire rear opening of the machine frame, and a strip 88 closes the space between the rear feet 91. The openings 89 in the sides of the frame may The noise of operation of the key-levers can be deadened to a large extent by placing a layer 96 of sound-deadening material on the key levers between the points of connection with the'bell-cranks and the front wall, and another layer 97 to the rear of said points and extending to the rear of the frame. These layers 96 and 97 of felt also further prevent the sound of the striking type-bars from emanating beneath the key-levers. The above-described sound-insulation will deaden much of the sound before leaving the typewriter-frame, the rest of the sound being readily absorbed by the hood. The

various. pads or sheets of sound-deadening ..material co-operate with the typewriter framework to form air-pockets within the frame; and the hood forms an air pocket or pockets outside of .the frame.

The bell-signal, which gives a warning at "the end of a line, would not be heard if contained within thehood. The bell-signal is therefore mounted so as 'to project to the exterior of the hood, and for this purpose a rod 100 threaded at-one end in the bracket 102 on. the machine projects outwardly to the side wall of the casing and carriesthe bell 101 at its'other end. .After the hood has been applied tothe machine,

the bell may be assembled on rod 100 and the one ordinarily used for the usual bellfull sound.

It will be understood that the cover and the body portion of the casing may be lined with any suitable sound-deadening material, such as felt.

The following claims are limited to in- Ventive organizations that are not disclosed in my co-pending application, No. 381,259, filed May 14, 1920.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. The combination with a typcwriting machine comprising a traveling carriage having a platen-frame mounted therein, and a platen-journaled in said platen-frame, of a sound-deadening casingfor the machine, said casing comprising a lower body part and an upper cover part hinged at the rear to said body part, there being a slot at the front between said body part and said cover part, and means connected to said platen and projecting forwardly through said slot whereby said platen maybe rotated from the front of the casing, said means operating in said slot when said carriage travels to the, right or left, and being provided with a finger-wheel outsideof said casing for rotating said platen in both directions.

2. The combination with a typewriting machine comprising a platen, a shaft upon which said platen is fixed, and a traveling carriage in which said shaft is mounted, of a sound-deadening casing for the machine having at its front a slot extending in the direction of carriage-travel, and means connected to saidplaten and projecting forwardly through said slot for rotating said platen from the front of the casing, said means being connected with the carriage to travel therewith, and comprising an op-- erating'shaft projecting through said slot, a gear fixed to the rearward end of said operating shaft, and a' gear fixed to one end of the platen-shaft and meshing with said first gear.

3. The combination with a typewriting machine comprising a case-shift platenframe, a shaft journaled in said frame, a platen fixed to said shaft and a traveling carriage in which said platen-frame is shiftable, of a sound-deadening casing for the machine having a slot extending in the direction of carriage-travel, and carriagesupported means connected. to said platen and projecting forwardly through said slotfor rotating said platen from the front of the casing, said means comprising an operating shaft extending through said slot, a gear fixed to the rearward end of said operating shaft, 2. gear fixed to one end of the platenshaft and meshing with said first gear, and a bracket fixed to said platen-frame and supporting said shafts to hold said gears in meshing engagement in the lowered and shifted positions of said platen.

4. The combination with a typewriting machine comprising a platen-frame, a shaft journaled in said frame and a platen fixed to said shaft, of a sound-deadeningcasing for the machine, means connected to said platen and projecting forwardly through said casing whereby said platen may be rotated from the front of the casing, said means comprising an operating shaft hav ing a forward part and a rearward part, a universal joint connecting said parts, and a gear fixed to the rearward end of said rearward part, a gear fixed to one end of the platen shaft and meshing with said first gear, and a bracket fixed to said platenframe and supporting said platen shaft and the rearward part of said operating shaft, to hold said gears in meshing engagement in the lowered and shifted positions of said platen, said universal joint permitting said rearward part of the operating shaft to move relatively to said forward part when the platen is shifted.

5. The combination with a typewriting machine comprising a carriage 1n which is mounted a platen-frame, a shaft journaled in said frame anda platen fixed to said shaft, of a sound-deadening casing for the machine, means connected to said platen and projecting forwardly through said casing whereby said platen may be rotated from the front of'the casing, said means comprising an operating shaft having a forward part and a rearward part, a universal joint connecting said parts, and a gear fixed to the rearward end of said rearward part, a gear fixed to one end of the platen shaft and meshing with said first gear, a bracket fixed to said platen-frame and supporting said platen shaft and the 'rearwardpart of said operating shaft, to hold said gears in meshing engagement in the lowered and shifted positions of said platen, said universal joint permitting said rearward part of the operating shaft to move relatively to said forward part when the platen is shifted, and a bracket fixed to said carriage and supporting the forward part of said operating shaft.

6. The combination with a typewriting machine having an open frame with an open base and feet to space said frame from a support on which. the feet rest, of sounddeadening means for said machine, including pads of sound-deadening material closing the sides and back of said frame, and

a pad of sound-deadening material resting on said support between said feet and ex tending upwardly to said base to close the opening the-rein, said pads co-operating with said frame to form an air-pocket.

7. The combination with a typewriting machine comprising a frame having openings in its back and side walls and in its base, of means for deadening sounds produced within said frame, including members of sound-deadening material for closing said openings and co-opera-tive with the frame to produce an air-pocket within the frame, and a sound-deadening casing enclosing said machine and forming an airpocket around the machine.

8. The combination with a typewriting machine having a frame with openings in its back and side walls and in its base, of means for deadening the sounds produced within said frame, comprising sound-deadening members for closing said openings, and a sound-deadeningmember extending across the inside of said frame above its base.

9. The combination with a typewriting machine having a frame with openings in its back. and side walls .and in its base, of means for deadening the sounds produced within said frame, comprising sound-dead ening members for closing said openings, a sound-deadening member extending across the inside of said f ame above its base, and

a sound-deadening casingenclosing said machine.

10. In a typewriting machine, the. combination with an open frame inclusive of an open base, of closures 0a sound-deadening material for the sides and rear of said frame, a closure of sound-deadening material for the bottom of said base, type-operating key-levers extending from rear to front within said base, and a transverse layer .of sound-deadening material surmounting said key-levers and co-operating with said frame and said bottom, side and rear closures to form sound-deadening air pockets.

11. The combination with a typewrit-ing machine comprising a frame having side and rear openings through which sounds produced in the operation of the machine may pass outside of said frame, of'sound-deadening means for said machine including closure pads of sound-deadening material for said side and rear openings, said closure pads attached to the frame and eo-operating therewith to form an air-enclosing and sound-absorbing chamber. j

' 12. The combination with a typewriting machine comprising a frame having rear, bottom and side openings through which sounds produced in the operation of the machine may pass, of sound-deadening means for said machine comprising closures 'of sound-deadening material attached to said frame for said rear, bottom and side the opening between said bottom closure and the line reached by the key-levers -when depressed.

14. The combination with a typewriting machine, of a base for said machine, said machine comprising avframe, a key-leverguiding comb at the front of said frame, and spaced above, the bottom of the frame, and means for supporting said frame on said base and spacing said frame' from said base,

.and sound-deadening means for said machine comprising a closure of sound-deadening material at the front of said frame beneath the key-levers, and extending from said base to the line reached by said key- -leversin their downward movements.

15. In combination, a typewriting machine having a front keyboard, and having a frame with openings in its back and side walls and in its base, and having type-operating key-levers extending from rear to front of said frame and projecting forwardly at the front of the machine, and means for producing interior air-pockets and deadening the sounds produced within said frame including closures of sounddeadening material for said openings, and also including a sheeting of sound-deadening material extending across said frame and surmountin-g said key-levers in rear of said keyboard.

16. 113,5, typewriting machine comprising a frame having rear, bottom and side. openings, in combination, a key-lever-guiding comb at the front of the machine, said comb being spaced above the bottom of said frame, thereby leaving an opening at the front of said frame, and sound-deadening means for said machine comprising a closure of sound-deadening material for each of said rear, bottom and side openings, and a closure ofsound-deadening material for said front opening below the comb.

17. In a typewriting machine, the combination with an open frame inclusive of an open base, of closures of sound-deadening material for the sides and rear of said frame,

a closure of sound-deadening material for' the bottom of said base, type-operating keylevers extending 'fromrear to front within said base, a transverse layer ofsound-deadening material surmounting said key-levers and co-operating with said bottom, side and rear closures to form soundd eadening airpockets, and a co-operating air-pocketing element extending from side to side of the base at its front portion and having a lower portion of sound-deadening material extending from said bottom closure up to the line reached by the depressed key-levers.

18. The combination with a typewriting machine comprising a frame having a keyboard-extension, type-bars and type-bar operating mechanism mounted in said frame,

said type-bar operating mechanism comprising key-levers pivoted in said frame andextending forwardly into said keyboard-extension, and bell-cranks having one arm pivoted to said key-levers at a point intermediate the'length of said key-levers and the other arm pivoted to said type-bars, of. means for deadening the sounds produced by the operation of the type-bar operating mechanism, said means comprising a generally horizontal layer of sound-deadening material overlying the portions of said keyleversforwardly of the points of connection to said bellecranks. v

19. The combination with a typewriting machine comprising a frame having 'a bottom opening, type-bars and type-bar-operat-ing mechanism mounted in said frame, said type-bar-operating mechanism comprising forwardly and rearwardly extending key-levers pivoted in said frame, of means for deadening the sounds of said type-bar operating mechanism, comprising a generally horizontal layer of sound-deadening material overlying said key-levers, and a sound-deadening closure for said bottom: opening ofvtheframe and co-operating with said layer and said frame to form a soundabsorbing air-pocket.

20. The combination with a typewriting machine having a frame with openings in its back and side walls and in its base and key-levers extending from front to rear of said frame, of means for deadening the sounds produced withinsaid frame comprising sound-deadening members for closing said openings, a sound-deadening sheet secured to said frame and extending thereacross above said key-levers, and a sounddeadening casing enclosing said machine.-

21. The combination withv a typewriting machine having a bell-signal for signaling the approach of the end of a line, of a sound-deadening casing for the machine, and means for mounting said bell-signal outside of said casing, sald-means comprising a support fixed at one end to said machine and extending outwardly through said casing, said bell-signal being fixed to said support at the other end thereof outside of said casing.

22. The Combination with a typewriting machine having a bell-slgnal for signaling the approach of the end of a line, and

having an outwardly-extending rearward end to co-operate with said bell-signal.

23. The combination with a typewriting machine having a bell-signal for signaling the approach of the end of a line, and means for ringing said bell-signal comprising a rearwardly-extending hammer, of a sound-deadening casing for the machine, and means for mounting said bell-signal outside of said casing, said last-named means comprising a bracket fixed on said machine, and a laterally-extending support fixed at one end in said bracket and extending through said casing, said bell-signal being fixed to said support at the other end thereof outside of said casing, said hammer having a laterally-extending rearward end to co-operate with said bell-signal.

24. The combination with a typewriting machine comprising a frame having openings in its back and side walls and in its base, key-levers extending from front to rear of said frame, type-bars and type-baract-uating members connected with said keylevers, of means for deadening the sounds produced within said frame, comprising sound-deadening members for closing said openings, a sound-deadening sheet secured to said frame and overlying said key-levers at the front of said type-bar-actuating members, and a sound-deadening sheet secured to said frame and overlying said key-levers to the rear of said type-bar-actuating members,

25. The combination with a typewriting machine having a bell, of a sound-deadening casing having an opening containing said bell, to permit said bell to project therefrom and to be heard outside of said casing said bell serving to practically close said opening in said casing, and strikingmeaas extending from said machine to said bell.

26. The combination with a typewriting machine comprising a carriage and a plate-n on said carriage, of a sordid-deadening casing for the machine, said casing having a slot therein, and means connected to rotate said platen back and forth, said means be ing disposed perpendicularly to the travel of said carriage and extending through said slot so that it may travel with the carriage and be operated from the outside of said casing, said rotating means having a flexible connection with said platen to permit case-shifting movements of the platen.

27. In a typewriting machine, the combination of a carriage, a platen, a platenframe to support said platen, said platenframe being mounted for case-shifting movements in said carriage, a finger-piece rotatably supported on said carriage, and

. means connecting said finger-piece with said with the gear on the platen-axle, a bracket to support one end of said shaft, said bracket being mounted on the platen-axle and swingable about the latter, a rotatable finger-piece, a bracket on said carriage to support said finger-piece, and a universal joint connecting said finger-piece with said shaft to permit the platen-frame to be shifted with said platen'relatively to the fingerpiece on said carriage.

29. In a typewriting machine, the combination of a carriage, a platen, a platenframe to support said platen, said platenframe being mounted for case-shifting movements in said carriage, a platen-axle, a bracket on the platen-frame to support the axle near one end thereof, a gear on said platen-axle, driving means comprlsmg a shaft disposed perpendicularly to the platenaxle, a gear on said shaft meshing with the gear on the platen-axle, a bracket to support one end of said shaft, said bracket being mounted on the platen-axle and swingable about the latter, a rotatable finger-piece connected with said shaft to rotate said platen, the forward end of said shaft being supported by said carriage, and means to permit the rear end of said shaft to be swung up and down with the platen during case-shifting movements of the latter.

30. In a typewriting machine comprising printing devices including key-levers extending-from the front to the back of the machine and pivoted at their rear ends on the frame of the machine, said frame comprising two sides joined at the rear by a cross-bar, four feet to support said machine, and'a sound deadening casing around said machine, the combination of means disposed above said key-levers to mufile the sound produced by the printing operations before chine, said casing having an opening to permit the bell to project therethrough to enable the bell to be heard outside of the casing, means connected to said platen and projecting forwardly through said casing whereby said platen may be rotated from the front of the casing, said means comprising an operating shaft having a forward part and a rearward part, a universal joint connecting said parts, and a gear fixed to the rearward end of said rearward part, a gear fixed to one end of the platen-shaft and meshing with said first gear, and a bracket fixed to said platen-frame and supporting said platen-shaft and the rearward part of said operating shaft, to hold said gears in meshing engagement in the lowered and shifted positions of said platen, said universal joint permitting said rearward part of the operating shaft to move relatively to said forward part when the platen is shifted. 32. In a typewriting machine, the com-- bination of a carriage-frame, a platen frame shiftable on said carriage-frame, a platen rotatably supported on said platenframe and shiftable with said platen-frame, a finger-wheel supported on said carriageframe and connected with the platen to rotate the latter back and forth, and means to permit said platen to be shifted relatively to said finger-wheel Without breaking the connection with said platen.

33. The combination of a sound-deylem ing casing having an opening therein, of a bell substantially closing said opening to cooperate with the casing for sound-deadening purposes. J

34. The combination with a typewriting machine having a frame with rear and side openings, of silencing means to intercept and absorb sound waves. and including a soundabsorbing rear pad secured to the typewriting machine and closing its rear opening, and also including pads of sounddeadening material secured in and closing the side openings of the machine, said closure pads of such a character that there is substantially no reflection of sound waves therefrom, said closure pads cooperatively forming a sound-deadening air-chamber.

35. The combination with a typewriting machine having a frame with rear, side and bottom openings, of silencing means to intercept and absorb sound waves and including a sound-absorbing pad mounted upon said frame and closing the opening in the back of thetypgwriting machine, and also including sound-absorbing pads mounted upon said frame and forming closures for the sides of the machine, and a soundabsorbing pad forming a closure for the bottom ofsaid frame, all of said closures of such a character that there is substantially no reflection of sound waves therefrom, said closures co-operatively forming a sounddeadening air-pocket.-

BURNHAM C. STICKNEY.

' WVitnesses EDITH B. LIBBEY,

J ENNIE P. THoRNE. 

